Ethereum Merge : End of PoW, Long Live PoS

Thanks to the ETH Merge, mining will lose its relevance — accordingly, the infrastructure will become more environmentally friendly.

The reason the change from PoW to PoS is called “the Merge” is because the already running beacon chain will merge with the existing Ethereum mainnet chain. This preserves the history of the network, its functionality, but crucially changes the consensus mechanism. The beacon chain will coordinate data and the production of new blocks via network validators, which will use economic incentives to secure the blockchain. 

Architecturally, the Merge is making use of the existing technology in Ethereum and supplementing it with what we need for the future. Current Ethereum clients, like Hyperledger Besu, will become known as “execution clients” and will handle state storage, block production, and smart contract interactions. “Consensus clients,” like Teku, will handle synchronizing state across the network and submitting transactions to the beacon chain. A new piece of technology called the “engine API” will allow these two clients to talk to each other extremely efficiently. All together, this new stack powers PoS with existing technologies and formats (like JSON RPC) and new ones such as REST APIs for the consensus clients.